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<head>
    <meta charset="UTF-8">
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    <title>Document</title>
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<body>
    <script>
        var arr = [55, 66, 77, 88, 99, 100]
        var arr1 = [10, 20, 30, 40]

        //平局数
        var ave = arr.reduce((preVal, curVal, curIndex) => preVal += curVal / arr.length, 0)
        console.log(ave)

        //拷贝 合并
        let newArr = [...arr]
        console.log(newArr)
        console.log('--------------------')
        let cloneArr = arr.slice(0)
        console.log(cloneArr);
        console.log('--------------------')
        let concatArr = [...arr, ...arr1]
        console.log(concatArr)

        /*    let newArr = [...arr]
           let cloneArr = arr.slice(0)
           let concatArr = [...arr, ...arr1]
   
           let newArr = [...arr]
           let cloneArr = arr.slice(0)
           let concatArr = [...arr, ...arr1] */

    </script>
</body>

</html>